Heavy mineral analysis of Eocene sands and sandstones of Nanka Formation, Cenozoic Niger Delta petroleum province

Abstract

The heavy minerals present in lithologic sand and sandstone units of Nanka Formation are mainly zircon, rutile, tourmaline, apatite, staurolite, and opaque minerals (Goethite, hematite, ilmenite), which are present dominant in weathered sandstones when analysed using petrographic varietal studies to infer provenance, diagenesis and source area weathering history. The low-diversity and relative abundance of heavy mineral assemblages are controlled by provenance and diagenetic processes, and these present limitations in accurate reconstruction of the paleo-history of these lithologic units using heavy minerals analysis alone. These lithologic Eocene units are derived from intensely weathered granitic and metamorphic source rocks and they are composed dominantly of matured polycyclic sediments.

Keywords

• heavy mineral
• diagenesis
• provenance
• weathering
• transportation
• mineral assemblages